When the pilot broadcast his intentions to conduct a touch-and-go on runway 25 there was no indication of any in-flight mechanical difficulty. The radar data time comparisons showed that following the last approach the pilot conducted a go-around rather than the planned touch-and-go. The decision to go-around normally is taken if a pilot assesses that a safe landing cannot be accomplished. Analysis of the radar data during the aircraft's climb phase on the go-around also indicated that the flight path and estimated airspeed were consistent with a normally operating aircraft in controlled flight. The aircraft was at 1100 feet asl (about 800 feet agl) when it disappeared off radar. About 15 seconds later, following a 4000 fpm rate of descent, the aircraft struck the terrain. There was no indication of a mechanical failure or pilot incapacitation. The environmental conditions on the night of the occurrence and the limited outside visual ground references in the vicinity of the Liverpool airport were elements conducive to spatial disorientation. During the go-around, false horizon and false climb illusions were both possible. A pilot's response to a false horizon illusion can result in incorrect flight control inputs for the real situation; false climb illusion can result in forward pressure on the control column and subsequent aircraft nose-down pitch attitude. At low altitude there is minimal time for a pilot to recognize an illusion and take the appropriate corrective action. The impact angle of the aircraft appeared to be more consistent with the nose-down pitch attitude associated with the false climb illusion. The complex skill set that a pilot requires to recognize and counter the effects of spatial disorientation are developed through flight instrument training, experience, and practice. The occurrence pilot, although appropriately licensed, had minimal instrument experience; consequently, he did not have the opportunity to fully develop the skills necessary to deal with the onset of spatial disorientation. Therefore, it is probable that the pilot experienced spatial disorientation that he could not overcome, lost situational awareness, and flew the aircraft into the ground.2.0 Analysis When the pilot broadcast his intentions to conduct a touch-and-go on runway 25 there was no indication of any in-flight mechanical difficulty. The radar data time comparisons showed that following the last approach the pilot conducted a go-around rather than the planned touch-and-go. The decision to go-around normally is taken if a pilot assesses that a safe landing cannot be accomplished. Analysis of the radar data during the aircraft's climb phase on the go-around also indicated that the flight path and estimated airspeed were consistent with a normally operating aircraft in controlled flight. The aircraft was at 1100 feet asl (about 800 feet agl) when it disappeared off radar. About 15 seconds later, following a 4000 fpm rate of descent, the aircraft struck the terrain. There was no indication of a mechanical failure or pilot incapacitation. The environmental conditions on the night of the occurrence and the limited outside visual ground references in the vicinity of the Liverpool airport were elements conducive to spatial disorientation. During the go-around, false horizon and false climb illusions were both possible. A pilot's response to a false horizon illusion can result in incorrect flight control inputs for the real situation; false climb illusion can result in forward pressure on the control column and subsequent aircraft nose-down pitch attitude. At low altitude there is minimal time for a pilot to recognize an illusion and take the appropriate corrective action. The impact angle of the aircraft appeared to be more consistent with the nose-down pitch attitude associated with the false climb illusion. The complex skill set that a pilot requires to recognize and counter the effects of spatial disorientation are developed through flight instrument training, experience, and practice. The occurrence pilot, although appropriately licensed, had minimal instrument experience; consequently, he did not have the opportunity to fully develop the skills necessary to deal with the onset of spatial disorientation. Therefore, it is probable that the pilot experienced spatial disorientation that he could not overcome, lost situational awareness, and flew the aircraft into the ground. 3.0 Conclusions 3.1 Findings The pilot was appropriately licensed to conduct the night VFR flight and was apparently medically fit. There was no indication of pilot incapacitation, and toxicology tests for drugs and alcohol were negative for both individuals. Blood analysis identified the presence of a low level of carbon monoxide (less than 10 per cent saturation) in both individuals; these values were consistent with levels observed in smokers. Records indicate that the aircraft had been maintained in accordance with existing regulations. The pilot transmitted his intentions to carry out a touch-and-go on runway 25 at the Liverpool airport. From a comparative analysis of radar data from the occurrence flight and the TSB representative flight, it was determined that the pilot conducted a go-around rather than a touch-and-go landing The aircraft's engine and flight control configuration at impact were consistent with settings used during a go-around phase of flight. Metallurgical analysis of the engine exhaust stacks indicated that the engine was operating at impact. The propeller blade damage and propeller cuts observed on trees along the wreckage trail indicate that the engine was developing power at impact. There was no mechanical anomaly identified that would account for the descent into the terrain. Conditions necessary for visual and vestibular illusions were present at the time of the occurrence. Spatial disorientation can lead to a loss of situational awareness, which in turn can result in an inappropriate control input. The pilot had minimal instrument experience. The impact angle of the aircraft was consistent with the nose-down pitch attitude associated with the false climb illusion. 3.2 Causes During the overshoot from the approach to the airport, the pilot probably lost situational awareness as a result of spatial disorientation, and unintentionally flew the aircraft into the ground.